Let-off mechanism for looms



(No Model.) s sheets-"sheet 1.

T. LOVBLIDGE. LET OPPMBGHANISM Fon Looms. j No. 355,617. Patented Jan@ 4, 1887.

'f |||lI 1f n @Iy (No Model.) S-'Sheets-Sheet 2.

T; LOVELIDGE. LET OFF MEGHAN'ISM POR LOOMS.

No. 355,617; Patented Jan. 4, 1887.

s sheetssheet a.

l(N0 Model.)

'17. LOVBLIDGB. LET OFF MECHANISM FOR LOMS.

.N0. 355,617. Patented Jan'. 4, 1887;

flu/@m501- T/wma L .Laye bldg@ WIL 6 66 UNITED STATES' PATENT Trice.

THOMAS LOVELIDGE, OF PHILADELPHIA, PNNSYLVANIA.

n LET-OFF IVECHANISM FOR LOOIVIS.

SPECIFICATION forming part ofLetters Patent No.355,61'7, dated January 4, 1887.

" Application filed June 24, 1886. Serial No. 206,087. (No model.)

To all whom it may concern.-

Be it known that I, THOMAS LovELIDGE, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Let Oft" Mechanisms for iooms, of which the following is a specificalon.

One object of myinvention is to so construct a let-oft" device for looms that there will be a delivery of warp-threads in proper accord with the requirements of the take-up, afurther object being to prevent any accidental delivery of warp-threads from the beam under the iniiuence of the strain upon the warpthreads in beating up, and a still further object of the invention being to readily permit a free delivery of warpthreads at such ti nies/as lmay be required.

In theaccompanying drawings, Figure l is a side view, partly in section, of suflicient of a loom to illustrate my improvedlet-'oif mechanism; Fig. 2, a perspective View of the let-0ff vmechanism detached from the loom; Figs. 3,

4,- and 5, diagrams illustrating the operation of the let-of5 Fig.- 6, a sectional view of part of the let-off device; Fig. 7, perspective views of part of the same, and Fig. 8 a detached View of the stop-plate. Fig. 9 is a diagram illustrating a modified plan of operating the letoff.

A represents the frame ofthe loom, and B the crank-shaft, the cranks of which are connected by rods a to the swinging lathe D of the loom, as usual.

The cloth-take-up mechanism may be of any desired character of positive takenp, lthis forming no essential part of my invention,

although I have shown in the drawings take-v up mechanism consisting of a ratchet-wheel, l, operated by a pawl, 2, carried by a lever, 3, hung to the frame of theloom, and having aslot, Il, for the reception'of a pin, 5,on the sword of the lathe, the spindle of said ratchetwheel l having a spur-pinion, 6, which engages with a spur-wheel, 7, on a spindle, 8, the latter having a spur-pinion, 9, engaging with a spur-wheel, l0, on the spindle of the takeup roll l1, the cloth-roll 12 being driven from said take-up roll by means of a belt, 13.

The Warp-threads x pass from the warpbeam X over rollers b b, carried by the upturned end d of the short arm of a lever, F,

which is hung to a bracket, e, on the frame of the loom, the long arm of the lever being provided with an adjustable weight, e, so that the tension upon y'the'warp-threads can'be properly regulated by shifting said weight.

The shaft of the warp-beam has a spurwheel, f, which gears into a pinion,.f, secured to the inner face of the hollowr drum G, the latter having projecting teeth g, acted upon by springs g', Figs. 6 and 7, which tend to project them to a certain extent beyond the periphery ofthe drum, the extent of projection being limited by contact of lugs c on the teeth with theinner face of the shell of the drum. These teeth act in conjunction With stop-projections 7L h h2 on a segmental plate,

H, so as to form an escapement for the druml vance will be stopped by contact with the proj ection h', and when this tooth is depressed the tooth in advance of it will be stopped by coutact with the projection h2, the depression-of the latter tooth bringing a fresh tooth into contact with the rst projection, lz, ofthe plate, so that there will be three movements of the Wheel to advance the same to the extent of one tooth. rlhe let-off of the warp-threads from the beam is thus 4governed by the depression of the teeth of the drum G, and this-is effected by means of pallets acting upon the teeth in succession.

There are in the present instance three pallets', t', i', and lZ-the iirst for operating the tooth in advance of the projection h, the second for operating the tooth in advance of the projection h', and the third for operating the tooth in advance of the projection hZ-the pallet t' being carried by a lever, J, and the pallets t" and 'i2 being formed on a sliding frame, K, which is connected to one arm ot' saidy lever and is operated thereby. As the lever J swings rearward, therefore, there is a simultaneous operation of the sliding frame K, and the pallets of the lever and frame are so arranged iii-respect to the projections of the plate H that the teeth of the drum G will be acted on IOC in succession by vsaid pallets, as will be vreadily understood on reference to the diagrams, Figs. e, 4, and 5.

The frame K has aslot, K', for the reception of the stud which carries the drum G, and the frame has an arm, to which is hung a weight, K2, whichtends to maintain the upper end of the frame in proper position for the action of the pallets upon the teeth of the drum.

The lever J has other pallets, m m, which serve as preliminary stops for the teeth, inadvanceof the stop h, when the lever J is in the position shown by dotted lines in Figs. 3 and 4.

Where a definite and positive take-up on each piek of the loom is required, the lever J may be operated by a cam or crank on the crank-shaft B of the loom, a cam, 4l, being shown for this purpose in Fig. 9. The Warpthreads in this case, however, should pass from the warp-beam over a let-off beam, 42, to which the escapemcnt device is connected, as it is necessary that the diameter of the let-ofi' beam shallalways be uniform where there is a definite movement of the same at stated intervals to effect theletoff of the warp. I prefer, however, to effect an intermittent let-off of the warp-threads in accordance with the requirements of the loom. This object I attain by operating thevlever J by means of a catch-arm, M, hung to the sword of the lathe, and connected at the outer end to a cord or wire, n, which passes over the upper roller, b, of the lever F, and is secured to a pin, '1), on the short arm of said lever.

As the cloth is taken up the short arm of the lever F is drawn down and the catch-arm M is permitted to engage with the lever J 5 but as soon as there has been a sufficient let-off of warp-threads to permit the short arm of the lever F to rise to the proper extent the catcharm M will be lifted clear of the lever J, and

the operation of the latter will be stopped nntil there is again a sufficient taking up of the cloth to warrant a further let-ofi" of warpthreads.

While there is always suicient slackin the warp to permit the easy shedding of the samev by the heddles or harness, the sudden longitudinal strain upon the warp-threads, due to the beating/up. of the lathe, has no effect upon thelet-ofi as, owing to the upturned end of ,the lever and its two rollers, this strain is exerted almost in a direct line with the fulcrum of said lever.

The use of three pallets and three projections on the retaining-plate permits a fine graduation in the let-off, and is preferred in looms for weaving fine goods, a coarser let-ofi` being available in looms for Weaving terry goods.

When it becomes necessary to provide for the free let-off of the warp-threads from the beam, as in making fringe on towels, scarfs, Ste., the teeth of the escapement-drum may be depressed by means of the forked end of a bar, P, guided on the loom-frame, so that said teeth will be free from the influence of the retainingprojections of the plate H, and each tooth is beveled on the rear side, so that the drum G can be readily turned backward to tighten the warp when necessary.

I prefer to provide each tooth with three portions, s, s', and s2, the portion s being the highest and being acted upon by the pallets, the portion s being somewhat less in height and being acted upon by the forked end of the releasing-bar P, and the portion s2 being the lowest and coming into contact with the stop-projections of the retaining-plate, this portion being beveled on the rear side, as specified.

To provide for the proper guidance of the Shanks of the teeth, I form the hub of the drum Gin two parts, one part being carried by one head, t, of the drum, and the other part by the opposite head, t', of the same, as shown in Figs. 6 and 7, each of these parts of the hub having alternating projections w and recesses w, the recesses of one part of the hub receiving the projections on the opposite part,

and the base of each recess and the end of the projection entering the same forming guides for one of the shanks of the teeth.

The drum G might be formed on or secured to the end of the let-off beam directly;but I prefer to connect it to the let-off beam by reducing-gearing, as shown, in order to permit a finer graduation of the let-off than would be possible if the drum were connected directly to the beam.

I claim as my i'nvention- 1. rIhe combination of thc let-off beam, an escapement-drum connected thereto and having movable teeth, stops for engaging said teeth, pallets for depressing the teeth, and means for operating said pallets, all substantially as specified.

2. The combination of the let-off beam, the escapement-drum connected thereto and having movable teeth, stops for engaging the said teeth, a lever having a pallet for operating on the teeth, lever-operating mechanism, and a ,sliding frame connected to the lever, and also provided with a tooth-operating pallet, all substantially as specified.

3. The combination of the let-ofi beam, the

,escapement-drum connected thereto, the movable teeth and stops therefor, a pallet-lever for operating said teeth, a lever having an upturned short arm, with upper and lower guides for the warp-threads, a catcharm connected to the said warp-lever and adapted to engage with the pallet-lever, and means for operating said catch-arm, all substantially as specified.

4. The combination of the let-ofic beam, the escapement-drum connected thereto and having movable teeth, stops for engaging the said teeth, pallets .for depressing the teeth, means for operating said pallets, and apresser-bar, whereby the teeth may be depressed independently of the pallets in order to free them from the control of the retaining-stops, all substantially as specified.

5. The combination of the movable teeth IIO with a drum having a two-part hub with enupturned short arm, with upper and lower gagingprojeetions and reoesses,forming guides guides for the warp-threads on said arm7 all for the Shanks of the teeth, all substantially substantially as specified.

as specified. In testimony whereof Ihave signed my name 5 6. Theoo'mbination of thepallets,stops, and to this specification-in the presence of two I5 releasing-bar, and mechanism for operating subscribing witnesses. the pallets, with the escapement-drnm having THOMAS LOVELIDGE.

stepped teeth, as set forth. 1 Witnesses:

7. The combination of the take-up and let- WILLIAM D. CONNER, b lo off mechanism with a warp-lever having an HARRY SMITH. 

